Power transmitting apparatus and control means therefor



Dec. 21, 1937. G. B. BAILEY 2,102,606

POWER TRANSMITTING APPARATUS AND CONTROL MEANS THEREFOR Filed April 29, 1935 GEORGE 8 E4125) [WT/EJ1 7015.

Patented Dec. 21 1 937 UNITED STATES PATENT OFFICE POWER, TEANEMITTING APPARATUS AND CONTROL MEANS THEREFOR George B. Bailey, Sharon, Mass. Application April 29,- 1935, Serial No. 18,721

4 Claims. (01'. 296-4) I This invention relates to improvements in claims whatever features of patentable novelty power transmitting apparatus and control means exist in the invention as a whole.

therefor. More especially it has to do with a Figure 1 is a diagrammatic showing of appanovel combination of means whereby the speed ratus embodying my invention; and

6 of a driven element may be maintained substan- Figure 2 is another similar showing, somewhat tially constant notwithstanding variations in more detailed. load and whereby the prime mover for such ele- Referring more particularly to the drawing, ment may be controlled in accordance with the there is disclosed a Diesel internal combustion load variations. engine I as representative of any prime mover Where a driven shaft is to be run at approxi- Whose drive shaft 2 is suitably connected to a 10 mately constant speed, or where the generation of differential unit 3 which, for purposes of illusa current with substantially constant voltage or tration, is shown in Figure 2 as a conventional cycles is desired, it has heretofore been necessary type of differential gear. A pinion t on the drive to maintain the speed of the prime mover correshaft 2 meshes with a ring gear 5 of the differspondingly constant, or substantially so, regardential unit and turns it about the axis m-zv. As- 15 less of variations in the load. Since the prime sociated with this ring gear and carried by it are mover must be capable of providing for the max-' pinions 6, 6 which may individually rotate about imum load whenever it occurs, its normal opertheir own axes yy- These pinions mesh with ating speed is usually determined by such load, gears l and 8, one of which is connected to a 30 and this speed is ordinarily maintained even when shaft 9 and the other to a separate shaft l 0. the load is greatly reduced. This is objection- On shaft 9 is mounted the armature ll of a able because needless power is generated in such dynamo having the electrical a acteristics oases during much of the operating time with f a S d Compound-Wound e consequent expensive consumption of fuel, maxator. It is well known that such a generator will imum wear on the moving parts and, in many deliver a current having a substantially uniform 25 instances, harmful effect on the prime mover voltage at a s s n lly n n p d or conitself. versely will run at a substantially constant speed It is a principal object of this invention to prowith a substantially constant voltage. The vide power transmitting and control means which t q e Output O this generator ay va y ma enable a driven element to maintain an ap ter ally Within its Working limits Without p 3O proximately constant speed while regulating the ciably affecting the potential of the current supspeed or operation of the prime mover in accordplied by t generator, providing the p ed O ance with the load imposed on the driven element. the generator is maintained Substantially @011- It is a feature of the invention that its principles stant.v

may be applied to various types of prime movers The other shaft l0 leading from the differen- 35 and to different methods f furnishing power, tial unit carries the armature l3 of a dynamo [4 In the accompanying drawing, the principles of having the electrical characteristics of a series my invention are illustrated in their application w d motor- In Such motor the que ears to a prime mover driving a dynamo having elecan inverse relation to the speed, the torque tend- 40 trical characteristics which cause it to run at a ing to pp Zero as the Speed pp s 40 substantially constant speed and with a subfi ystantially constant voltage regardless of varying The main wires l5 and [6 leading from brushes current output or input within the limits of its I1 and i8 respect v y, On the ato commucapacity. As shown somewhat diagrammaticah tater 19, having the shunt-field winding 20 con 4:; ly, the electrical output of such a dynamo may nected therewith and, as seen in Figure 1, may be employed directly as power, or the rotation of thence lead to a storage battery 2!, or other voltits shaft may be utilized to drive machinery or age stabilizer, and thence to a load represented apparatus where a substantially uniform speed I by a series of lamps 22. The wires l5 and [6 are is desired such as, for example, an alternator for also connected by wires 23 and 24 respectively producing alternating current. While the best With brushes 25 and 26 on the commutator 21 50 mode in which I have contemplated applying the 'of the armature l3, and included in this circuit principles ot my invention is shown in t'ne-accoinis the series-field winding i3 of the motor. it. panying drawing, this is to be taken as merely Wires i5 and it are also connected by wires illustrative for it is intendedi-hat the patent 28 and. 3t with device in which responds to shall cover by suitable expression in the appended electrical changes in the line 15-46 and thereby affects the control of the prime mover I. Wire 32 from the device 3i leads to a storage battery 33, or other source of power, from which wire 34 runs to a reversible motor mechanism 35 which controls the fuel or power input to the prime mover. Wires 36 and 3'! also connect the reversible motor mechanism with the device 3|. This device may be a volt meter which has been fitted with contact points in such a manner that an electrical circuit is completed upon an increase in voltage above a desired voltage or a second electrical circuit is completed upon a decrease in voltage below the desired voltage.

Referring now to Figure 2 and especially to the differential unit, it will be seen that gears I and 8 and the pinions 6, 6' are shown as of the same size. This is of course not necessary but is shown so to avoid any consideration of gear ratios. It is well known that in such a differential if one gear, for example gear 8, is driven in the direction of arrow a and the ring gear 5 is simultaneously driven in the direction of arrow e, then the pinions 6 will rotate in the direction of arrow b, pinion 6' in the direction of arrow 0, and the other gear I will be driven in the direction of arrow d. The speed of the latter will be a function of the speeds of the gear 8 and the ring gear 5. Advantage is taken of this last mentioned characteristic of the differential and, as will presently appear, the gear 8 is positively driven in direction opposite to that of gear I, so that the gear 8 actually is used as a driving gear just as is ring gear 5.

As previously stated, it is desired to run shaft 9 at a substantially constant speed and to vary the speed or operation of the prime mover in accordance with the load on this shaft. Let it be assumed that shaft 9 and the generator I2 are being driven at a suitable speed and that the generator is producing a current flow in line I5, I6 sufiicient to satisfy the demand of the load represented by the lamps 22, and also to drive the series-wound motor I4. That is to say, the prime mover I is being driven by some power input and. drives the ring gear 5 of the differential while motor I4 is being driven by the current flow from generator I2 and likewise drives the gear 8.

Inasmuch as the speed on generator I2 is to be substantially constant the torque which it exerts is directly proportional to its output or load and therefore approaches a maximum as its load approaches a maximum. On the other hand, if the speed of the prime mover is to vary as its power output and it is to supply the power required by the system, as the load on generator I2 approaches a maximum the speed and the torque of the prime mover should both approach their maximum in which case the speed of the series motor I4 must decrease and approach its minimum. However, as mentioned before, the torque of a series motor increases as its speed decreases which is as required in this instance because.

the increase in the torques exerted by both the generator I2 and prime mover I on an increase in load must be balanced by the torque exerted by series motor I4. In other words, series motor I4 becomes an automatic torque balancer for the whole system, torque on which may be constantly changing due to varying load conditions. Except as the load is varying the system must be balanced, that is to say, the torque of the prime mover times its speed, plus the torque of the series motor times its speed, equals the torque of the generator times its speed.

. The major purpose of the invention is to pro- 2.

vide for the maintenance of the generator speed substantially constant. Its torque will vary directly with its load. Therefore if the torque of the generator is reduced by a falling off of the load, the power required to drive it at the desired speed is less. Accordingly, upon the falling off of the load, the invention provides for the reductionof power furnished by both the prime mover and the motor I4. This is accomplished as follows. As the load on the generator 32 or shaft 9 falls off, the speed is momentarily increased and causes an increase in voltage along the line I5, I6 and this is communicated by wires 29, 38 to the voltage responsive device 3!. Such increase in voltage causes a circuit to be established through wires 32 and 3'! and the reversible motor mechanism 35 to effect a reduction in the fuel or power supply to the prime mover. This causes the latter to slow down and deliver less power to the ring gear 5. Since the speed of the latter is thereby reduced, the speed of gear I and also the generator would likewise be reduced unless the speed of gear 8 was increased to maintain the desired speed of the generator.

However, as mentioned before, the characteristic of the series motor I i which drives gear 3 is such that it is always endeavoring to increase its speed and in doing so its torque automatically decreases until a point is reached where the system is balanced.

Conversely, if the load on the generator is increased, it will momentarily slow down and the voltage in line I5, I6 will drop. This affects the device 3| to establish a current flow through wires 32 and 36 and the reversible motor mechanism 35 to effect an increase in the fuel or power supply to the prime mover I. The latter speeding up the ring gear 5.

series motor I4 increases until the system is againbalanced. It is to be noted that in any event the speed of generator I2 remains substantially constant because the voltage on the system remains substantially constant within the limits:

of accuracy of voltage operated device 8|, speed with which the prime mover responds to power input control device, and size of storage batteries 2|, all of which are controllable factors.

By a proper selection of apparatus, the desired control can be exercised with most satisfactory results, and the speed of shaft 9 maintained with approximate uniformity. The generator will de-= liver a current as required by the load and at a substantially constant voltage.

means therefor comprising, in combination, a prime mover; a dynamodriventhereby; power 75 If an alternator 38 is also driven by shaft 9, then the al- And if the power of transmitting means connecting them including a differential unit; a second dynamo connected to said unit and adapted to impart power thereto; and control means actuated by variations in the electrical output of the first said dynamo, occasioned by changes of the load thereon, for controlling the power applied to said unit by both the prime mover and the second dynamo to maintain the speed of the first said dynamo substantially constant.

2. Power transmitting apparatus and control means therefor comprising, in combination, a prime mover; a direct current generator; power transmitting means connecting them including a diflerential unit; a direct current motor electrically connected with said generator and connected with said unit so as to impart power thereto; and control means responsive to changes in the electrical output of said generator, occasioned by changes in the load thereon, for varying the power output of the prime mover in accordance with said load changes; the said motor being capable of responding to said changes in the electrical output of the generator to vary the power imparted by the motor to the unit, thereby to maintain the speed of the generator substantially constant.

3. Power transmitting apparatus and control means therefor comprising, in combination, a Diesel engine; a direct current generator; a differential power transmitting unit connecting them; a series-Wound motor mechanically connected to said unit and electrically connected to said generator in such manner that the operation of said motor corresponds with the electrical output of the generator; and control means responsive to changes in the electrical output of said generator and capable of varying the operation of said Diesel engine in accordance with the load on said generator.

4. Power transmitting apparatus and control means therefor comprising, in combination, a differential power transmitting unit; a Diesel engine connected therewith and arranged to impart a driving torque thereto; a direct current generator connected to said unit and arranged to receive a driving torque therefrom; a series wound motor mechanically connected to said unit and arranged to impart a driving torque thereto; and control means responsive to changes in the electrical output of said generator for varying the driving torque imparted by the engine in accordance with the load on said generator; the said motor being electrically connected to said generator in such manner as to be actuated in accordance with changes in the electrical output therefrom to balance the torque imparted to the unit, whereby the operating speed of the generator is maintained substantially constant.

GEORGE B. BAILEY. 

